Feline Lower Urinary Tract Disease (FLUTD)

(Formerly Feline Urologic Syndrome (FUS))

By Nancy Otten, Animal Health Technologist

What is Feline Lower Urinary Tract Disease?

Cats with FLUTD suffer from all or some of the following symptoms:  bloody urine, straining to urinate, frequent urination, urinating in places other than the litter box, painful urination and excessive licking of the urethral opening.  It is a disease that affects the cat’s bladder and most commonly affects cats that are around four years of age.

What causes the disease?

20% of the time the problem will be bladder stones.  Another 20% of the time the cause will be urethral blockage (the urethra becomes blocked with a combination of mucous and crystals or sometimes even tiny bladder stones.)  Less frequently,  urinary tract infections, cancer, or trauma (like being hit by a car) can be the cause of the trouble.  However, about 50% of the time the cause of the symptoms cannot be determined even with extensive testing.  This is called idiopathic cystitis.   

How do crystals and stones form in the bladder?

There are two main types of crystals and stones that form in the bladder.  The most common is struvite (sometimes called triple phosphate.)  Struvite crystals are made up of three different elements:  magnesium, ammonium, and phosphorous.  These crystals form when the urine is very concentrated (ie. dark in colour and strong smelling) and its pH is very high (alkaline.)  The other type of crystal and stone that forms is calcium oxalate.  These also form when the urine is very concentrated but when the pH is very low (acidic.) 
 

How is the cause of the FLUTD symptoms diagnosed?

The first thing that the veterinarian will do is to feel the cat’s bladder through the abdominal wall.  A sure indication of a blocked urethra is a big, hard bladder about the size of a peach.  This is a medical emergency.  If treatment is not immediately implemented, the cat will die of toxicity.  When the bladder is completely full, the kidneys stop doing their job of filtering toxins out of the blood stream.  These toxins build up and initially cause vomiting, nausea and appetite loss.  Eventually (within 48 hours) they will cause death.  If the bladder feels normal, a urine sample would be needed to determine if infection or crystals are the problem.  A radiograph (x-ray) may be recommended to rule out the possibility of bladder stones.  The veterinarian might also recommend blood testing to rule out other diseases. 

How do we treat the problem?

Treatment depends on the cause.  If your cat’s urethra is blocked, it needs to be unblocked immediately.  Inserting a urinary catheter into the cat’s urethra in order to push the blockage back into the bladder where it can be dissolved solves this problem.  If bacteria are found in the urine, the problem is solved with antibiotics.  Crystals in the urine can be dissolved by changing the diet to alter the urine pH.  If x-rays show that your cat has a bladder stone, the type of stone will need to be determined.  If it is a calcium oxalate stone, it must be removed surgically.  If it is a struvite stone, it can be dissolved in the bladder by changing the diet to lower the urine pH.  If it is determined that your cat is suffering from idiopathic cystitis, two things need to happen.  The first thing that you will need to do is to treat your cat with cartrophen and glucosamine.  The bladder has a mucous lining that protects the bladder wall from any noxious elements that may be in the urine.  One of the elements of this layer is called glycosaminoglycan or GAG.  It has been found that cats with idiopathic cystitis have reduced levels of GAG so the protective layer in the bladder is weak.  That leaves the bladder susceptible to inflammation which causes the FLUTD symptoms.  The cartrophen and glucosamine will help to replace this protective layer.  The second thing that you will need to do is to increase your cat’s water consumption.  The easiest way to do this is to feed your cat wet food (at least 50% of the cat’s diet should be wet.)  Also, it is essential to have fresh water available at all times.  This may mean that you will need to refresh his water bowl twice a day.  It has been found that cats don’t like drinking out of a container where his whiskers touch the side when drinking.  Offer water in a wide dish and fill it to the brim.  Pay close attention to how and where your cat likes to drink water.  If your cat prefers to drink out of the glass on your bedside table, let him.  Set up a system so that you both have a glass there.  If he prefers to drink out of the toilet, keep it clean and flush lots!  You might have to be creative.  Cats also love broth and the water that you drain from your canned tuna. 

How can we prevent FLUTD from happening?

Although your cat can develop FLUTD while on a good quality diet, in the majority of cases it is found that the affected cat has been eating a cheap, poor quality food.  The most important thing that you can do for your cat in the way of prevention is to feed him a good quality diet.  These diets are specially formulated so that the urine produced by your cat is slightly acidic which discourages the formation of struvite crystals.  These diets also limit your cat’s magnesium intake (magnesium is a component of struvite crystals.)  Of course good quality foods are more expensive.  Remember that the less expensive the food, the less attention the manufacturer has paid to details such as urine pH and magnesium content.  All foods are not created equal and you definitely get what you pay for.  Do your cat an enormous favour and buy quality food.  You will both benefit in the long run.    

Another defense against FLUTD is to increase water intake.  It is recommended that cats should be fed a combination of 2/3 dry food and 1/3 wet unless he has a history of FLUTD.  Then he should be fed at least 50% wet food.  Kittens should be exposed to wet food early so that they will like wet food as adults.  For more tips on increasing your cat’s water intake, see the above section on treating idiopathic cystitis.